In a router network, consistent routing tables must be distributed from a central point to all of the interface ports of the network. In a unicast distribution mechanism, a single sender sends a message to a single receiver, which may be required to send an acknowledgment to the sender. In a multicast distribution mechanism, a single sender simultaneously sends an identical message to multiple receivers, each of which may be required to return an acknowledgment. The receiver may choose if it wants to see this message, and consequently not all receivers in the network see this message. In a broadcast distribution mechanism, a single sender simultaneously sends an identical message to multiple receivers, none of which can return an acknowledgment. In a multiple source broadcast distribution mechanism, multiple senders simultaneously send multiple messages to multiple receivers, none of which returns an acknowledgment, although each receiver can interpret information from any of the receiver's paths.
A heartbeat mechanism is defined as a consistently timed message between a sender and a receiver. A snapshot is defined as the current image of a table at an instant of time. That is, the image is dynamic and constantly changing.
Additional background information can be found in the following references: “CCIE Professional Development Routing TCP/IP,” Vol. 1, MacMillan Technical Publishing, Indianapolis, Ind., 1998; “Routing in the Internet” by Christian Huitema, Prentice Hall, Upper Saddle River, N.J., 2000; and “Internetworking with TCP/IP” by Douglas Comer, Prentice Hall, Upper Saddle River, N.J., 2000.
At all cost, message storms must be prevented. A message storm occurs when communication points saturate, because all resources are spent on processing incoming messages and doing no other work. This could shut down the entire router.
Desired in the art are a method and system for efficiently and reliably distributing and maintaining routing tables in a multiple-source, multiple-receiver communication network environment. Additionally desired are such a method and system that avoid saturation of communication points, thereby preventing message storms.